I have the 07 110 RK SE3, Cobalt Blue, Axtell cylinders & pistons 575 red shift cams thunder max auto tune with the true dual Rinehart’s. The sound has kept many cagers from switching lanes into my lane when the bike roars at them. It sounds very healthy at idle. Also lets every one think I may have that Harley bad boy attitude, even though I have seasoned well with age. HA HA Good luck to you as there are many different choices out their.